Dion Moult 0b122ae1f5 ifcviewer: GPU cull drives rendering under IFC_GPU_CULL=1
Promote the compute cull from a validation shader to the actual draw
driver.  With the gate on, the CPU cull fan-out is skipped and MDI
consumes gpu_indirect_buffer / gpu_visible_ssbo directly.

- uploadGpuCullStaticBuffers() pre-fills per-mesh DrawElementsIndirect
  commands and a mesh_base prefix sum so the compact shader can scatter
  survivors into a fixed per-mesh range.  Instance count for each
  command is zeroed by a tiny reset dispatch, then the compact shader
  atomically writes survivors and increments instanceCount.
- Draw loop branches on the gate: single CCW MDI with all mesh
  commands.  Fwd/rev winding split, LOD selection, and HiZ are still
  CPU-path-only; reflected instances render with wrong winding under
  this gate (step 3b).
- Once-per-second readback of each model's indirect buffer populates
  the survivor / visible-object / visible-triangle stats so the
  [frame] line reflects what the GPU actually drew.

Known regression: sub_draws is the full mesh count per model (~172k on
the test dataset) vs the handful of non-empty commands the CPU path
produces.  Command-processor overhead from zero-instance sub-draws is
what drives the FPS drop, not the cull itself (0.05 ms).  Compacting
non-empty commands requires glMultiDrawElementsIndirectCount, a GL 4.6
entrypoint not exposed by Qt's QOpenGLFunctions_4_5_Core; deferring to
3a-followup so we don't bolt a getProcAddress loader into the renderer
mid-restructure.

IFC_GPU_CULL is off by default, so this does not affect normal runs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-04-23 21:32:24 +10:00
2026-04-23 10:58:57 +02:00
2025-12-19 18:53:14 +05:00
2026-04-23 21:32:24 +10:00
2026-04-19 10:35:04 +02:00
2026-01-26 17:10:03 +05:00
2026-04-21 21:48:15 +02:00
2026-04-10 17:29:46 +05:00
2023-09-14 09:29:20 +02:00
2026-02-18 09:09:46 +11:00
2025-08-28 20:05:45 +02:00
2025-08-28 20:05:45 +02:00
2026-04-13 19:38:25 +05:00
2026-04-13 19:40:25 +05:00

IfcOpenShell

IfcOpenShell is an open source (LGPL) software library for working with Industry Foundation Classes (IFC). Complete parsing support is provided for IFC2x3 TC1, IFC4 Add2 TC1, IFC4x1, IFC4x2, and IFC4x3 Add2. Extensive geometric support is implemented for the IFC releases IFC2x3 TC1 and IFC4 Add2 TC1. Extending with support for arbitrary IFC schemas is possible at compile-time when using C++ and at run-time when using Python.

In addition to a C++ and Python API, IfcOpenShell comes with an ecosystem of tools, notably including IfcConvert (an application to convert IFC models to other formats), Bonsai (an add-on to Blender providing a graphical IFC authoring platform), and many other libraries, CLI apps, and more. Support is also provided for auxiliary standards such as BCF and IDS.

For more information, see:

Development is sponsored through your generous donations!

Open Collective Contributors

Contents

Name Description License Service
bcf Library to read and write BCF-XML and query OpenCDE BCF-API modules LGPL-3.0-or-later PyPI Anaconda-Server Badge
bonsai Add-on to Blender providing a graphical native IFC authoring platform GPL-3.0-or-later Official GitHub Unstable Chocolatey
bsdd Library to query the bSDD API LGPL-3.0-or-later PyPI
ifc2ca Utility to convert IFC structural analysis models to Code_Aster LGPL-3.0-or-later
ifc4d Convert to and from IFC and project management software LGPL-3.0-or-later PyPI
ifc5d Report and optimise cost information from IFC LGPL-3.0-or-later PyPI
ifcbimtester Wrapper for Gherkin based unit testing for IFC models LGPL-3.0-or-later
ifcblender Historic Blender IFC import add-on LGPL-3.0-or-later*
ifccityjson Convert CityJSON to IFC LGPL-3.0-or-later PyPI
ifcclash Clash detection library and CLI app LGPL-3.0-or-later PyPI
ifcconvert CLI app to convert IFC to many other formats LGPL-3.0-or-later* Official GitHub
ifccsv Library and CLI app to export and import schedules from IFC LGPL-3.0-or-later PyPI
ifcdiff Compare changes between IFC models LGPL-3.0-or-later PyPI
ifcedit CLI wrapper for ifcopenshell.api IFC model mutation functions LGPL-3.0-or-later PyPI
ifcfm Extract IFC data for FM handover requirements LGPL-3.0-or-later PyPI
ifcmax Historic extension for IFC support in 3DS Max LGPL-3.0-or-later* Official
ifcmcp MCP server for querying and editing IFC building models LGPL-3.0-or-later PyPI
ifcopenshell-python Python library for IFC manipulation LGPL-3.0-or-later* Official GitHub PyPI Anaconda Anaconda Docker AUR AUR Unstable Pyodide WASM Wheels tag
ifcpatch Utility to run pre-packaged scripts to manipulate IFCs LGPL-3.0-or-later PyPI
ifcquery CLI tool for querying and inspecting IFC building models LGPL-3.0-or-later PyPI
ifcsverchok Blender Add-on for visual node programming with IFC GPL-3.0-or-later GitHub
ifctester Library, CLI and webapp for IDS model auditing LGPL-3.0-or-later PyPI

The IfcOpenShell C++ codebase is split into multiple interal libraries:

Name Description License
ifcgeom Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcgeom_schema_agnostic Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcgeomserver Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcjni Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcparse Internal library for IfcOpenShell LGPL-3.0-or-later*
ifcwrap Internal library for IfcOpenShell LGPL-3.0-or-later*
qtviewer Internal library for IfcOpenShell LGPL-3.0-or-later*
serializers Internal library for IfcOpenShell LGPL-3.0-or-later*
S
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Python 36.2%
C 3.9%
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JavaScript 0.3%
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